In a wireless communication system such as OFDM (Orthogonal Frequency Division Multiple Access), a base station performs scheduling by considering combination of a time-axis sample and a subcarrier as a unit based on downlink reception quality information reported from each mobile station to improve use efficiency in a frequency domain. A combination of a time-axis sample and a subcarrier is referred to as a resource block (Non-Patent Documents 1, 2). A resource block in 3GPP is defined in Non-Patent Document 4, on pages 22-24.
FIG. 17 is a block diagram showing a configuration of this kind of a wireless communication system. Areas (60), (61) with which base stations (20), (20a) are able to communicate respectively are referred to as cells. Base station (20) also divides cell (60) into areas (50a), (50b) and (50c), and base station (21) divides cell (61) into areas (51a), (51b) and (51c), and these base stations are capable of communicating with each of areas respectively. Each divided area is referred to as a sector (referring to Non-Patent Document 3).
FIG. 18 is a block diagram showing a detailed configuration of mobile station (10) and base station (20) in FIG. 17. It shows a block diagram of constituent components required to perform scheduling resource blocks. Control unit (101) in mobile station (10) outputs a resource block received from the base station to reception quality measurement unit (102), and performs an operation of transmitting the reception quality information outputted from reception quality measurement unit (102) to the base station.
Reception quality measurement unit (102) in mobile station (10) measures a reception quality of a resource block. The reception quality of the resource block is calculated by for example SINR (Signal to Interference and Noise Ratio) (Non-Patent Document 4). SINR of the resource block is calculated from received power in a downlink reference symbol unit (a portion in which a reference signal of the resource block is stored) by using the following Equation (1).
                                          SINR            RB                    ⁡                      (                                          B                0                            ,                              F                n                                      )                          =                              S            ⁡                          (                                                B                  0                                ,                                  F                  n                                            )                                                                          ∑                                  m                  =                  1                                M                            ⁢                                                          ⁢                              S                ⁡                                  (                                                            B                      m                                        ,                                          F                      n                                                        )                                                      +            W                                              (        1        )            
M represents a total number of sectors in the whole system except for the sector to which file mobile station is connecting at the moment, Bm represents a sector, and sector B0 at m=0 represents a sector (Serving Cell) to which the mobile station is connecting at the moment, and a sector at m>0 represents an adjacent sector in the identical base station or a sector in the neighboring base station. Mobile station (10) is capable of measuring the received power of the reference symbol unit of the resource block in these sectors B0-BM (referring to Non-Patent Document 4). Fn represents nth resource block. Furthermore, SINRRB(B0,Fn) represents received SINR of a signal transmitted from sector B0 in resource block Fn, and SRB(Bm,Fn) represents a received power of a signal transmitted from sector Bm in resource block Fn. W is a thermal noise power.
Mobile station (10) reports the reception qualities measured for each resource block by the above-mentioned calculation to base station (20) at regular intervals (Non-Patent Document 5, 11.5 CQI Reporting for Scheduling).
Control unit (201) in the base station transmits downlink data or reference symbols to mobile station (10), and informs the reception quality information reported from mobile station (10) to resource allocation unit (202) and MCS judgment unit (203). Control unit (201) in the base station performs an error correction coding and data modulation in response to MCS (Modulation and Channel Coding Scheme) determined by MCS judgment unit (203) based on the reception quality information when transmitting downlink data.
FIG. 19 is an illustration showing a configuration of resource allocation unit (202) in base station (20). Allocation determination unit (2021) in resource allocation unit (202) performs resource block allocation (scheduling) for each mobile station by using reception quality reports of each resource block from mobile station (10).
FIG. 20 is an illustration showing a configuration of MCS judgment unit (203) in base station (20). MCS determination unit (2031) in MCS judgment unit (203) selects MCS having maximum transmission rate, for example where an error rate generated is less than or equal to a desired value, for the reception qualities of the resource blocks allocated to each mobile station based on the allocation of the resource blocks in resource allocation unit (202) and the reception quality information.
It is proposed that the interference between cells in OFDM mobile communication system as mentioned above can be reduced by allocating resource block and resetting MCS in Patent Documents 1-3.    [Patent Document 1] Japanese Patent Kokai Publication No. P2005-328519A    [Patent Document 2] Japanese Patent Kokai Publication No. P2006-33826A    [Patent Document 3] Japanese Patent Kokai Publication No. P2006-522503A    [Non-Patent Document 1] Y. Ofuji, et al., “IEICE Technical Report [Radio Communication Systems (RCS)]”, Vol. 104, No. 598, pp. 101-106, 2006    [Non-Patent Document 2]H. Fujita, et al., “IEICE Technical Report [Radio Communication Systems (RCS)]”, Vol. 106, No. 168, pp. 121-125, 2006    [Non-Patent Document 3] 3GPP TR 21.905 V8.1.0(2007-06), “Cell” pp. 8, “Sector” pp. 23    [Non-Patent Document 4] 3GPP TR 36.211 V8.0.0(2007-09), pp. 21-24, pp. 36-41    [Non-Patent Document 5] 3GPP TS 36.300 V8.2.0(2007-09), pp. 52